a grandfather clause for existing solar customers. Maine is considering changing its net metering energy billing rules. On September 13, 2016, the Maine Public Utilities Commission proposed a new rule, and then held a public hearing on October 17. The proposal would consider changing net metering billing rules and is expected to be completed in early 2017. In the Maine legislature, Assistant Majority Leader Sara Gideon (D-Freeport) introduced a new bill to increase Maine's solar industry tenfold and implement a market-based program, replacing the current net metering policy. In 2015–2016 in Maine, a collective group of environmentalists, consumer representatives, installers of solar power, and utilities proposed a bill in the state legislature suggesting the replacement of net metering with a market-based "pay for production" program. One provision of the bill proposes that Central Maine Power (CMP) and Emera, Maine's two main utilities, establish long-term contracts with utility developers and solar owners allowing them to purchase solar power generation. Subsequently, they would bid the generation into New England electricity markets. This arrangement could last existing net metering customers up to 12 years. A competitively set regulated price would be paid by the aggregators in order to compensate for owner costs. In turn, the utility aggregators would capitalize on the return on sales. In March 2017, state legislators in both the Maine state House and Senate began writing legislation that would preserve retail net metering. The bills would make it temporary in the short term. In early 2017, the Maine Public Utilities Commission approved new limits that will eventually phase out net metering, beginning in 2018. The House bill would "fully save retail net metering." A group called the Maine Environmental Priorities Coalition supports the legislation. The Senate bill would reinstate net metering while regulators examine "how advanced metering can help better determine the costs and benefits of rooftop solar." The solar industry is supporting that bill. In February 2017, a group called the Natural Resources Council of Maine "vowed to continue fighting new net metering restrictions." In December 2017, the Maine Public Utilities Commission voted to delay implementing the state's new solar rules, which would phase down the net metering compensation for rooftop solar customers. Net metering supporters, led by the Conservation Law Foundation, filed a lawsuit to overturn the PUC's decision. The Maine Supreme Judicial Court is set to hear arguments in the case on December 13, 2017. The Maine